Patch Name: PHKL_12945

Patch Description: s700 10.20 OnLine JFS (Advanced VxFS) cumulative patch

Creation Date: 97/10/20

Post Date:  97/10/23

Repost:	97/10/27
	The documentation did not fully describe the conditions
	under which the problem was seen.  The missing information
	was added.
	Since the actual patch bits were not altered there is no
	reason for systems having PHKL_12945 installed to update
	to the reposted version.

Hardware Platforms - OS Releases:
	s700: 10.20

Products:
	HP OnLineJFS (Advanced VxFS) B.10.20

Filesets:
	AdvJournalFS.VXFS-ADV-KRN

Automatic Reboot?: Yes

Status: General Superseded

Critical:
	No (superseded patches were critical)
	PHKL_8735: CORRUPTION
	PHKL_8388: CORRUPTION

Path Name: /hp-ux_patches/s700/10.X/PHKL_12945

Symptoms:
	PHKL_12945:
	Process hang at exec() time on PA8000 (PA-RISC 2.0)
	systems using Advanced VxFS (OnlineJFS).

	PHKL_9415:
	Executables residing on a VxFS (JFS) file-system would no
	longer execute after being marked for VX_DIRECT operation.
	A typical scenario would be as follow:
	   # cd /vxfs
	   # cp /usr/bin/ksh .
	   # ./ksh
	   # cc vxdirect.c -o vxdirect
	   # ./vxdirect ./ksh
	   # ./ksh
	   ./ksh: ./ksh: cannot execute
	See the vxfsio(7) man pages for details on VX_DIRECT.

	PHKL_8735:
	Under OnlineJFS, when very large writes (e.g. >phymem/16)
	are done to JFS file(s), old data can appear in the middle
	of the newly written file(s).

	PHKL_8388:
	Data corruption can occur if HP OnLineJFS is installed and a
	very large write (over a megabyte) is done to a JFS file.  A
	sequence of 1 - 8191 zeros can appear in the middle of the
	data just written.

Defect Description:
	PHKL_12945:
	If the executable was marked for "large text page"
	(chatr +pi L) then the process would hang at exec()
	time if one (or more) of the conditions below is (are) met:
	- the executable text size is > 128KB,
	- the file system (where the executable resides) was mounted
	  with mincache=direct or convosync=direct,
	- the executable was marked for VX_DIRECT operation by an
	  application through an ioctl().
	To reproduce:
	# cp /sbin/who /vxfs   # Use who(1) as an example.
	# cd /vxfs
	# chatr +pi L ./who
	# ./who          # Execute command, process is hung.
	You cannot kill this process, but you *can* kill the shell
	running it.

	PHKL_9415:
	The execve() kernel routine was asking for a KERNEL IO to
	read in the a.out header, but the VxFS code handling direct
	IOs (VX_DIRECT) was generating a USER IO.

	PHKL_8735:
	OnLineJFS breaks large write requests into multiple direct
	I/O's.  Depending on the size of the data block, the
	beginnning and end of a direct I/O request may not align on
	the block boundaries. In these cases, the data is handled
	through buffer cache.

	After the first direct I/O, the subsequent iteration may
	begin with a write that has data starting in the middle
	of the buffer. If this write passes the current EOF, the
	buffer is simply allocated and filled with new data. If
	this buffer happens to be one that previously used to hold
	old data, the old data remains in the portion that is not
	overwritten by the new data. Writing this buffer to disk
	corrupts the file.

	The fix is to check against the correct file size so the
	first buffer of the subsequent iteration will be read in
	from disk to contain the correct data written in the last
	iteration.

	PHKL_8388:
	The problem can be reproduced with this test program:

	  char buf[2097152];

	  main()
	  {
	        int fd;

	        memset((void *)buf, 'A', sizeof(buf));
	        fd = creat("A.dat", 0644);
	        write(fd, buf, 512);
	        write(fd, buf, sizeof(buf));
	  }

	Every byte of the file should contain the character 'A'.
	This works fine on UFS.  It also works on VxFS as long as
	HP OnLineJFS is not installed.  But with HP OnLineJFS, a
	sequence of null bytes appears in the middle of the file
	(not at the boundary between the writes, but in the middle
	of the second write).

SR:
	1653180810 1653223669 5003336933 5003344184

Patch Files:
	/usr/conf/lib/libvxfs_adv.a(vx_dio.o)

what(1) Output:
	/usr/conf/lib/libvxfs_adv.a(vx_dio.o):
		vx_dio.c       $Date: 97/10/20 09:43:17 $ $Revision:
			 1.7.98.11 $ PATCH_10.20 (PHKL_12945)

cksum(1) Output:
	3848220841 12532 /usr/conf/lib/libvxfs_adv.a(vx_dio.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes:
	PHKL_8388 PHKL_8735 PHKL_9415

Equivalent Patches:
	PHKL_12946:
	s800: 10.20

Patch Package Size: 70 KBytes

Installation Instructions:
	Please review all instructions and the Hewlett-Packard
	SupportLine User Guide or your Hewlett-Packard support terms
	and conditions for precautions, scope of license,
	restrictions, and, limitation of liability and warranties,
	before installing this patch.
	------------------------------------------------------------
	1. Back up your system before installing a patch.

	2. Login as root.

	3. Copy the patch to the /tmp directory.

	4. Move to the /tmp directory and unshar the patch:

		cd /tmp
		sh PHKL_12945

	5a. For a standalone system, run swinstall to install the
	    patch:

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_12945.depot

	5b. For a homogeneous NFS Diskless cluster run swcluster on the
	    server to install the patch on the server and the clients:

		swcluster -i -b

	    This will invoke swcluster in the interactive mode and
	    force all clients to be shut down.

	    WARNING: All cluster clients must be shut down prior to the
		     patch installation.  Installing the patch while the
		     clients are booted is unsupported and can lead to
		     serious problems.

	    The swcluster command will invoke an swinstall session in which
	    you must specify:

		alternate root path  -  default is /export/shared_root/OS_700
		source depot path    -  /tmp/PHKL_12945.depot

	    To complete the installation, select the patch by choosing
	    "Actions -> Match What Target Has" and then "Actions -> Install"
	    from the Menubar.

	5c. For a heterogeneous NFS Diskless cluster:

		- run swinstall on the server as in step 5a to install
		  the patch on the cluster server.

		- run swcluster on the server as in step 5b to install
		  the patch on the cluster clients.

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_12945.  If you do not wish to retain a
	copy of the original software, you can create an empty file
	named /var/adm/sw/patch/PATCH_NOSAVE.

	Warning: If this file exists when a patch is installed, the
	         patch cannot be deinstalled.  Please be careful
		 when using this feature.

	It is recommended that you move the PHKL_12945.text file to
	/var/adm/sw/patch for future reference.

	To put this patch on a magnetic tape and install from the
	tape drive, use the command:

		dd if=/tmp/PHKL_12945.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None